Discriminative and Affective Processing of Touch: Associations with Severity of Skin-picking

Abstract

Skin-picking is a common behavior in the general population that generally serves emotion regulation (e.g., reduction of tension). However, recent research suggests it may also be associated with changes in tactile processing sensitivity. Along these lines, the present study examined whether the severity of skin-picking (SOSP) is related to discriminative and affective touch processing. A total of 160 participants (59 males, 101 females, mean age = 31 years) completed two tactile discrimination tests (two-point discrimination, surface texture discrimination), as well as a well-validated affective touch paradigm (delivery of soft/slow touch, which is found to be generally pleasant). A hierarchical regression analysis was carried out to investigate the association between SOSP, age, sex, and indicators of tactile sensitivity. Replicating previous findings, females reported higher SOSP. While the performance in the discrimination tests did not predict SOSP, affective touch processing was associated with SOSP. Participants with high SOSP reported an urge to pick their skin after being softly touched. This seems paradoxical since previous findings have suggested skin-picking may be carried out to manage negative affective states. Our findings add to the literature describing altered sensitivity and responsivity to specific tactile stimuli in individuals with excessive skin-picking.

Atypical cerebellar activity and connectivity during affective touch in adults with skin-picking disorder

“…In summary, the main finding of the current study refers to reduced lobule VIII activity in patients with SPD. This observation is in line with previous studies using behavioral approaches (e.g., Odlaug et al, 2010 ; Wabnegger & Schienle, 2022 ), structural neuroimaging (e.g., Grant et al, 2013 ; Blum et al, 2018 ), as well as functional neuroimaging (e.g., Odlaug et al, 2016 ) that described SPD-related deficits in motor control. A future investigation could evaluate Inhibitory Control Training (ICT) for patients with SPD.…”

“…Further, an investigation (without fMRI) by Schienle and Wabnegger ( 2022 ) already pointed to dysfunctional motor responsivity related to SPD. In this study, soft brushing of participants’ forearms elicited an increased urge to pick the skin in those with elevated skin-picking severity.…”